Internal Mass Transfer Resistance Research Articles

Desulfurization of Zawia Refinery Diesel Using Adsorption Fixed Bed Process

The study focuses on the dynamic modeling of a fixed-bed adsorber for the adsorption of sulfur compounds in diesel fuel. The model considers non-ideal plug flow behavior and velocity variation along the column, providing a more realistic representation of the adsorption process. Additionally, internal mass-transfer resistances due to pore diffusion mechanisms are incorporated into the model. The study investigates adsorption performance by examining different flow rates (5 cc/min, 10 cc/min, 15 cc/min, and 20 cc/min) and inlet concentrations ranging from 586 to 100 ppm. The bed height is constant at 30 cm. The behavior of various parameters, such as bed utilization, breakpoint time, film mass transfer coefficient, and height of the adsorption zone, is analyzed. The results indicate that a sharp front of the breakthrough curve is observed, followed by the broadening of the tail of the breakthrough curve. The breakthrough curve represents the adsorbate concentration in the effluent stream over time. The investigation reveals that a high flow rate of 20 cc/min and a high inlet concentration yield better overall bed capacity utilization for the adsorption system. This means that the bed is more effectively utilized at higher flow rates and higher inlet concentrations, leading to improved adsorption performance. In conclusion, high flow rates and high inlet concentrations are favorable for enhancing the adsorption system's performance in terms of bed utilization. These results provide valuable insights for optimizing the design and operation of fixed-bed adsorbers that remove sulfur compounds from diesel fuel.

Fixed-bed column adsorption modeling using Zr biocomposites for fluoride removal

ABSTRACTThis research involved conducting continuous adsorption experiments to assess fluoride elimination from drinking water achieved by utilizing biocomposites created from the peels of oranges and apples, which were impregnated with zirconium (Zr), to form BOP-Zr and BAP-Zr, respectively. The findings from the experimental data indicate that BOP-Zr and BAP-Zr are effective biosorbents with a solid ability to remove fluoride selectively. Additionally, these biosorbents were found to be stable, as they do not release Zr into the treated water. Notably, these environmentally friendly biosorbents are derived from renewable sources and enhance the value of waste materials. The study employed various empirical models, including Bohart-Adamas, Thomas, Yoon-Nelson, BDST, Clark, Yan, and Woolborska, to elucidate the mechanisms and crucial parameters involved in fluoride adsorption within packed bed columns. The Yan model demonstrated the highest correlation among these models, indicating a chemical adsorption process with kinetics following a pseudo-second-order pattern. BOP-Zr and BAP-Zr exhibited a maximum adsorption capacity of 59.3 and 47.5 mg/g, respectively, under a flow rate of 4 mL/min and an inlet fluoride concentration of 25 mg/L. The analysis of mass transfer coefficients revealed that the primary step governing the adsorption procedure was diffusion through pores. Consequently, the study conclusively establishes that BOP-Zr and BAP-Zr biocomposites, originating from lignocellulosic biomass remains, present a practical and competitive choice for eliminating fluoride from water. These materials surpass waste materials in performance and rival more expensive options in efficiency and performance.

Equilibrium and fixed-bed kinetics study on hazelnut skin polyphenols extraction using choline chloride –lactic acid-based NADES and water as solvents

This paper focuses on the potential of Hazelnut Skin, a waste product from the food industry, as a source of polyphenols in line with circular economy principles. Two environmentally friendly solvents, water and Natural Deep Eutectic Solvent (NADES), were utilized for the extraction process. First of all, the extraction potential of both solvents was evaluated and an amount of 172.2 mg/g and 470.2 mg/g of free polyphenols per unit mass of solid were obtained using Water and NADES respectively. The solid–liquid equilibrium was also deeply investigated observing that two main phenomena are involved during the process: solubilisation and adsorption. An innovative model based on the combination of Langmuir isotherm and the introduction of a partitioning coefficient to describe a progressive approach to the solubility limit was then proposed to characterize the thermodynamics of the system. While NADES showed promising results compared to water in terms of amount of polyphenols extracted, there are several challenges that need to be addressed before implementing NADES in large-scale extraction processes. Hence, in this study continuous tests were conducted to observe the behavior of both solvents in a fixed-bed column that emulates a section of an industrial belt extractor. The experimental data collected were fitted by means of the Broken Intact Cells (BIC) Model. It was found out that the internal mass transfer resistance is the controlling one and the correspondent mass transfer coefficient estimated was 1.3·10-3 min−1 for Water and 6.67·10-4 min−1 for NADES. The results obtained from this study can be considered valuable resources for improving the existing methods of extracting polyphenols from waste matrices using water and for developing innovative approaches that utilize NADES as a solvent.

Influence of ultrasound-pretreated convective drying of Roselle (Hibiscus sabdariffa L) leaves on its drying kinetics and nutritional quality

The drying kinetics and the nutritional qualities of Roselle (Hibiscus sabdariffa L) leaves as affected by ultrasound pretreatment during hot air drying were investigated in this work. Ultrasound frequency and power at 20 kHz and 600 W, respectively, were used for the experiment. Roselle leaves were subjected to ultrasound pretreatment in distilled water for 0 min (untreated), 5 min (UD5), 10 min (UD10) and 15 min (UD15) before hot air drying. The result showed that UD15 samples had about 47% reduction in drying time compared with the untreated samples. The effective moisture diffusivity of the treated and untreated samples ranged from 1.21 to 3.29 × 10−1m2/s. The Page and Logarithmic models best described the drying behavior for the untreated and treated samples respectively. The values of the mass transfer Biot number (ratio of internal mass transfer resistance to external mass transfer resistance) for all the samples ranged from 0.9032 to 1.2391. The samples of UD10 and UD5 had the highest amount of carotenoid and vitamin C contents, respectively, amongst the untreated and treated samples. The total color change of the treated samples were significantly lower than the untreated samples after drying. Drying of Roselle leaves is usually done using convective drying method with its attendant's effects such as long drying time, loss of nutrients and high energy usage. But this work showed that application of ultrasound pretreatment during drying of Roselle leaves can significantly reduce the drying time and at the same time retain the nutritional quality of the dried treated samples.

Modeling and simulation of trickle bed reactors for the purification of 1-butene

Abstract In this contribution, a mathematical model of an industrial trickle-bed reactor employed in the purification of a C4 cut by selective hydrogenation of acetylenic or dienes compounds to obtain high purity 1-butene is presented. A reaction network of ten reactions is included in the model, with kinetics expressions and parameter estimation obtained from previous experimental studies on a commercial catalyst. Internal mass transfer resistances in the catalyst particles are significant; therefore the reaction-diffusion equations must be solved. External mass transfer resistances in the liquid phase were retained, while those in the vapor phase were negligible. The model was employed to analyze the reactor behavior by varying the inlet molar flow rate of hydrogen, the operating pressure, inlet temperature and the level of activity of the catalyst, taking into account its deactivation. It was demonstrated that the mass transfer resistances, inside and outside the catalyst particles, have a significant impact on the selectivity, but a careful operation of the reactor can improve the selectivity and extent the catalyst life. On the other hand, an alternative system was proposed, with two beds and a distributed input of H2, which led to a significant improvement in the selectivity.

Investigation on the catalysis performance of metal-doped zeolites on ring-opening acidolysis reaction

Metal-incorporated zeolites as heterogeneous Lewis acid were applied in the ring-opening acidolysis of ethylene oxide with acrylic acid to prepare 2-hydroxyethyl acrylate (HEA). The catalysis characteristics, including Lewis acid strength and internal mass transfer resistance, were systematically investigated to facilitate the rational design of zeolite catalysts. Through modifying the Lewis acid strength of zeolites via different metals (Sn, Zr and Ti) incorporation and the internal mass transfer resistance of zeolites from the particle size, pore diameter or pore structure, it was found that the increased Lewis acidity can accelerate both the main and side reactions, resulting in the high activity but low selectivity of zeolite catalysts; the enhanced internal diffusion was the key to limiting subsequent cascade alcoholysis side reactions as well as the decline of catalytic performance. Based on these findings, Zr-containing zeolites featured with moderate Lewis acidity and uniform intracrystalline mesoporosity were designed and prepared, presenting excellent catalysis and recycling performance. These results demonstrated the great potential of the developed zeolite catalysts for the green synthesis of HEA as well as the similar ring-opening acidolysis of epoxides.

Micro-mechanism insights into the adsorption of anionic dyes using quaternary ammonium-functionalised chitosan aerogels

The development of adsorbents with outstanding adsorption capacities, wide versatility, and excellent recyclability for the removal of organic dyes remains a challenge. In this study, a quaternised chitosan-based aerogel (QCSA) was fabricated via a facile method to effectively treat concomitant anionic dyes. Porous QCSA with high hydrophilicity, nontoxicity, excellent thermal stability, and sustainability exhibits adsorption properties superior to most previously reported adsorbents. The equilibrium adsorption capacities for Congo red, Sunset yellow, and Methyl orange were 1259.6, 550.2, and 607.5 mg/g, respectively. Notably, the spent QCSA exhibits excellent cyclic performance. The multilayer adsorption, external–internal mass transfer resistance, and adsorption on the active site models were employed to enable a more accurate description of the dynamic characteristics, confirming that double-layer chemisorption was the dominant process. A quantitative analysis of the electrostatic potential and the independent gradient model further verified that electrostatic interactions, hydrogen bonding, and van der Waals forces led to the highly efficient adsorption of dye molecules. Therefore, the eco-friendly and recyclable QCSA is a promising adsorbent for trapping anionic dyes from aquatic systems.

Experimental study and kinetic modeling of methanol conversion to propylene with co-feeding of C4 and C5/C6 hydrocarbon cuts over a ZSM-5 catalyst.

Extensive experimental data were used to develop a comprehensive kinetic model for the methanol to propylene (MTP) process over a ZSM-5 catalyst. Preliminary experiments were performed to determine the reaction conditions that would ensure the absence of external (film) and internal mass transfer resistances. The kinetic experiments were subsequently carried out at 420-500 °C under conditions where mass transfer limitations were absent. A detailed reaction network was proposed for the MTP process based on the experimental product distribution and various reported kinetic models in the literature. According to the first series of experiments (without C4 and C5/C6 recycle streams) conducted at various temperatures, the best yield for propylene production was achieved at 480 °C with a water to methanol ratio of 0.7. Subsequently, kinetic experiments were performed at 480 °C and a water to methanol ratio of 0.7 using feeds with different amounts of C4 and C5/C6 hydrocarbons as recycle streams. Species material balances for the integral tubular reactor along with power-law rate functions and the Arrhenius equation for rate constants were employed in an optimization algorithm to obtain the kinetic parameters. The predictive ability of the model was checked against experimental data, and the kinetic parameters were validated by additional experiments.

Kinetics, mass transfer, and thermodynamics of Ethyl Hexanoate synthesis using heterogeneous catalyst

The present work delineates insight into the heterogeneous esterification of hexanoic acid to Ethyl Hexanoate. Efficacy was tested using Indion-225H and Amberlyst-15 as a catalyst. The effect of various process parameters such as mole ratio, temperature, catalyst loading, and speed of agitation was investigated for maximum ester conversion. A maximum yield of 81.31% was obtained in 4 h of reaction time at optimized values of 70 °C, 1:3, Hexanoic acid: Ethanol mole ratio, 12% catalyst loading, and 10% molecular sieves at an agitation speed of 300 rpm. The possibility of internal and external mass transfer resistance was evaluated. Effective diffusivity De-A was calculated as 3.58 × 10–11 m2/s. The energy of activation was calculated as 40.39 kJ mol-1. Kinetic and adsorption equilibrium constants were investigated for the LHHW model. Thermodynamic parameters such as enthalpy of activation, Gibbs free energy, and entropy of activation were predicted. Functional groups were confirmed using infrared spectroscopy.

Optimization of Liquid Organic Hydrogen Carrier (LOHC) dehydrogenation system

In this paper, the perhydrodibenzyltoluene dehydrogenation flowsheet has been simulated. Modelling of the dehydrogenation reactor has been performed using the 1-D model. External and internal mass transfer resistances are also considered. Non-isothermal pellet condition has been considered for simulating the dehydrogenation reactor. The flowsheet simulation has been carried out in DW-Sim v 6.5.2 integrated with the reactor model coded in Python. NET. The dehydrogenation reactor is operated at a feed temperature between 523 K −613 K, a wall temperature of 623 K and 653 K, and a reactor pressure maintained at 1.2 atm. The amount of catalyst required for the perhydrodibenzyltoluene (PDBT) dehydrogenation reactor is evaluated such that the conversion reaches 99%. The process flowsheet has been simulated to produce 10 Nm3/hr of industrial-grade hydrogen. The effects of feed temperature, wall temperature, and hydrogen burner efficiency on various system requirements, including catalyst weight, energy supplied to the dehydrogenation reactor, areas of the heat exchanger, and hydrogen production from the reactor, have been discussed. Preliminary cost optimization based on the heat exchangers and catalyst at various feed temperatures, reactor wall temperature, and hydrogen burner efficiency has been carried out.

Effective Maxwell−Stefan diffusion model of near ambient air drying validated with experiments on Thomson seedless grapes

AbstractWith 8% of the world's grapes being dried into raisins, grape drying constitutes a sizable part of agricultural revenue. The drying process in the developing regions of the world struggles with a lack of reliable drying techniques and rising energy costs. In this work, we report a systematic study to elucidate the intrinsic drying kinetics of Thomson seedless grapes. The grapes are subjected to drying by warm air (40−55°C) rather than hot air (>60°C), which has the advantage of producing the sought‐after green raisins. The air velocity is varied between 0.05 and 0.15 m/s to isolate the effect of external mass transfer resistance. A 1D mathematical model was developed that incorporates the effects of internal diffusion and external mass transfer resistance as well as the effects of temperature and relative humidity on the kinetics and driving forces. In addition, the model incorporates a novel thermodynamic model to describe the vapour pressure of water at the surface of the grape. The uniqueness of the model is that it combines thermodynamics and mass transfer in a single framework. Therefore, the parameters that describe the evaporation are the same parameters that describe the internal diffusion within the matrix, making the model robust. This robust, experiment‐trained model can be reliably transferred to develop detailed computational protocols to model cost‐effective grape drying processes in the field.

Hydrodesulfurization of 4,6–Dimethyldibenzothiophene on NiMoP/γ–Al2O3 catalyst under reactive distillation conditions in a micro trickle bed reactor: solvent and temperature effect

Abstract In this work, the influence of pressure and temperature experimentally applied on reactive distillation (RD) under lower conditions than conventional hydrotreating (HDT) processes, the hydrodesulfurization (HDS) reaction of 4,6–dimethyldibenzothiophene (4,6–DMDBT) molecule and the experimental performance of a down-flow micro trickle bed reactor (micro-TBR) with n–dodecane and decalin were studied. Thermodynamic analyses to evaluate hydrogen solubility in liquid hydrocarbons and evaporation for n–dodecane and decalin as lineal and cyclic representative solvents, respectively, were considered. It was possible to define experimental conditions, producing a small deviation of the plug flow model (PFM) and diminished the gas–liquid (G–L) mass transfer limitation as determined from a reactor model at 2.5 MPa. The axial dispersion model (ADM) and PFM models adjust the experimental data at 2.5 MPa operational pressure and the 4,6–DMDBT conversion obtained was ca. 20–50% using n–dodecane; 1.5 times higher when decalin was using. This behavior was due to the liquid hydrogen fraction of n–dodecane was two times higher than for decalin for all operational pressures. In this sense, the use of n–dodecane as a solvent decreased the mass transfer resistance at the G–L and liquid–solid (L–S) interphases. The internal mass transfer resistance in the G–L interphase not only depends on the diffusivity of the solvent, but it also depends on both, the temperature and hydrogen pressure, finding that the RD conditions with n–dodecane are viable in the treatment of sterically impaired molecules in HDS processes.

Ultrasound-assisted synthesis of ethyl hexanoate using heterogeneous catalyst: Optimization using Box-Behnken design

Ultrasound-assisted synthesis of ethyl hexanoate was studied in a solvent-free system using Amberlyst-15 as a heterogeneous catalyst. The effect of reaction parameters was evaluated by employing Box Behnken Design. Maximum conversion was obtained as 83.9% experimentally with operating temperature 60 °C, ethanol to hexanoic acid molar ratio as 3, 60% duty cycle, 11% catalyst loading, 10% molecular sieves, and 80 W input power which were optimized through one parameter at a time. The optimal conditions for maximum 86.66% conversion obtained by Box Behnken Design operated in Response Surface Methodology were 62.8 °C temperature, 3.31 ethanol to hexanoic acid molar ratio, and 51.58% duty cycle. The absence of external mass transfer resistances was proved by evaluating Mear's criterion. Thiele modulus and effectiveness factor were determined to study the influence of internal mass transfer resistance qualitatively. The kinetics of the heterogeneous reaction was modeled using Langmuir-Hinshelwood model. The activation energy was calculated as 24.61 kJ/mol.

Fast and continuous synthesis of 2,5-furandicarboxylic acid in a micropacked-bed reactor

Oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) is of great importance for the production of biopolymer. It is regarded as a representative of the heterogeneous process, in which the reactant in the gas phase and liquid phase interact with each other over the solid catalysts. Due to the low mass-transfer efficiency and co-existence of O2 and organic compounds in the batch reactor, low catalytic efficiency and safety concerns hiders the commercial application. Herein, a micropacked-bed reactor was used to realize the efficient and ultrafast continuous-flow synthesis of FDCA. Au/CeO2 was used as a catalyst and O2 was used as a green oxidant. Owing to the enhanced gas − liquid mass transfer efficiency, an HMF conversion of 100% and an FDCA selectivity of 90 % were achieved within only 41 s, which represents a space–time-yield of 1–2 orders of magnitude higher than that of traditional reactors. By virtue of the minimized internal and external mass transfer resistances, kinetic parameters of the reaction were determined. The rate constants were more than one order of magnitude higher than those of other strategies. In addition, the oxidation of HMFCA to FFCA was determined to be the rate-controlling step. Overall, this work not only delineates an efficient strategy for synthesizing FDCA from HMF, but also opens a new avenue for enhancement of heterogeneous reactions suffering from limited mass transfer.

Sustainability assessment of acid-modified biochar as adsorbent for the removal of pharmaceuticals and personal care products from secondary treated wastewater

This study investigated the adsorption behavior and sustainability of biochar to remove four pharmaceutical and personal care products (PPCPs). The biochar (PEBC) was prepared via slow pyrolysis of empty palm bunch (PEB) at three temperatures (250–750 °C). To improve the adsorption capacity further, PEBC450 was acid treated with H2SO4 to develop PEBC450-A. The adsorption behavior of target pollutants (methyl paraben (MPB), carbamazepine (CZP), ibuprofen (IBP), and triclosan (TCS)) onto PEBC450-A was studied in batch experiments, and phenomenological and statistical models were applied to understand the sorption mechanism. Results demonstrated that the adsorption system was able to achieve fast equilibrium (in 4 h), with maximum adsorption capacities as 60.2 mg/g (MPB), 51.7 mg/g (CZP), 38.8 mg/g (IBP), 35.4 mg/g (TCS). The modeling results showed heterogeneous adsorption of PPCPs involving the participation of multiple functional groups in parallel and non-parallel orientations. The mass transfer kinetic models identified the internal mass transfer resistance as the rate-limiting step. The PPCPs adsorption was significantly affected by the change in solution pH and the presence of humic acid. However, no substantial change in PPCPs removal was observed in the presence of co-existing ions and different ionic strengths. In multi-pollutant systems and real water samples, PEBC450-A maintained more than 75% removal of target pollutants, indicating the developed material as a promising adsorbent for wastewater treatment. The sorption mechanism was found to be channel diffusion, hydrogen bonding, n-π and π-π interactions, and van der Waals force. The comparative life cycle assessment of PEBC450-A and commercial activated carbon showed that the total impact contribution of PEBC450-A was 20 times less than commercial activated carbon. The overall finding makes PEBC450-A a low-cost and sustainable adsorbent for water treatment.

Advanced modelling of adsorption process on activated carbon

To gain a deeper insight into the adsorption kinetics mechanism, the adsorption of p-chlorophenol (PCP) from water, cyclohexane, and heptane on surface chemistry modified activated carbons was modeled by the general rate (GR) differential mass transport model, which takes into account external and internal mass transfer resistance. Due to the fact that the particles of AC are characterized by a wide particle size distribution (PSD) and pore diameter distribution (PDD), which are usually not considered for the simulation, our experimental dates were modeled with the GR model, in which PSD and PDD were included. It was found that, for organic phases, mainly the slow surface adsorption–desorption process controls mass transfer. In the case of water, the mass transfer was controlled by molecular diffusion in pores or by slow surface adsorption depending on AC. It was also shown that neglecting the PSD can lead to errors in the evaluation of the values of the adsorption model parameters, whereas, on the other hand, the pore diameter distribution can be successively approximated by average pore diameter.

Modeling and optimization of a honeycombed adsorbent bed for efficient moisture capture

Adsorption-based atmospheric water harvesting has received significant interest owing to its promise of decentralized water supply and a wide applicability. In this study, the adsorbent bed is specially designed and optimized for efficient moisture capture. A transient three-dimensional non-equilibrium model has been developed that takes both internal and external mass transfer resistances into account. It is found that the simulation results agree better with the experimental results, which indicates the reliability of the model. Then this model was applied to investigate the influence of the adsorbent bed structure, and the operating parameters on the transient distributions of the adsorbent temperature, adsorption kinetics, dynamic up-taken moisture capture, mass transfer resistance and relative capture efficiency of the adsorbent bed. ASLi30 (Activated carbon fiber + Silica gel + 30 wt% LiCl)-vapor is selected as the working pair. It has been found that generally, the effects of the air channel aspect ratio on the investigated indexes are negligibly small. A thinner layer thickness and a smaller air channel length characterize an excellent moisture capture, small vapor transport resistance and faster adsorption kinetics. By considering different parametric variations for performance optimization and the effect of operating conditions, these results provide important insights and design guidelines of adsorbent bed for efficient moisture capture.

The relative importance of internal and external physical resistances to mass transfer for caffeine release from apple pectin tablets

The relative importance of the physical resistances to mass transfer have been explored by using halved 13 mm diameter apple-pectin tablets containing caffeine, in different external stirring environments within a beaker containing simulated gastric fluid. The effects of different external (outside of the tablets) mass-transfer resistances to the tablets created through two different stirrer types and stirrer speeds, and different internal (inside of the tablets) mass-transfer resistances created through different tablet concentrations and thicknesses, have been studied. These studies enable internal diffusion coefficients of caffeine through the apple pectin matrix to be estimated, as well as estimating the external mass-transfer coefficients from benzoic acid dissolution, which are in the range of 6.5 × 10-6 m/s – 2.4 × 10-5 m/s for the 0.6 mm thick tablets and 4.0 × 10-6 m/s – 1.6 × 10-5 m/s for the 7 mm thick tablets. The diffusion coefficients for different caffeine concentrations in the apple pectin half-tablets have also been calculated in this study. The diffusivity of caffeine in the 7 mm half-tablets with 1% caffeine through 99% pectin was around (1.8 ± 0.5) × 10-10 m2/s. This study points towards the development of multifilm mass-transfer theory for food digestion to create a more fundamentally based understanding of in-vitro digestion systems as an addition to the use of realistic in-vitro food digestion apparatus and give a better correlation between in-vitro and in-vivo digestion tests.

Approximate Models of Microbiological Processes in a Biofilm Formed on Fine Spherical Particles

This paper concerns the dynamical modeling of the microbiological processes that occur in the biofilms that are formed on fine inert particles. Such biofilm forms e.g. in fluidized-bed bio-reactors, expanded bed biofilm reactors and biofilm air-lift suspension reactors. An approximate model that is based on the Laplace–Carson transform and a family of approximate models that are based on the concept of the pseudo-stationary substrate concentration profile in the biofilm were proposed. The applicability of the models to the microbiological processes was evaluated following Monod or Haldane kinetics in the conditions of dynamical biofilm growth. The use of approximate models significantly simplifies the computations compared to the exact one. Moreover, the stiffness that was present in the exact model, which was solved numerically by the method of lines, was eliminated. Good accuracy was obtained even for large internal mass transfer resistances in the biofilm. It was shown that significantly higher accuracy was obtained using one of the proposed models than that which was obtained using the previously published approximate model that was derived using the homotopy analysis method.

Modeling and optimization of ammonia process: Effect of hydrogen unit performance on the ammonia yield

The main object of this research is the development of a mathematical framework to simulate a commercial ammonia plant and obtaining the optimal operating conditions of process at steady state condition. The considered ammonia plant consists of steam and autothermal reforming reactors, low and high temperature shift converters, hydrogen purification section, methanation, and ammonia synthesis reactors. The catalytic reactors are heterogeneously modeled based on the mass and energy balance equations considering heat and mass transfer resistances in the gas and catalyst phases. In addition, an equilibrium model is applied to simulate the absorption column. Then, the accuracy of developed framework is investigated against plant data. The results show that the internal mass transfer resistance in the commercial catalyst limits the syngas production in the reforming section. In the second step, an optimization problem is formulated to enhance the ammonia production considering safety and operating limitations. The formulated optimization problem is handled employing the genetic algorithm. The results show that more syngas production in the optimized hydrogen unit is one of the main reasons for higher ammonia synthesis in the considered plant. Applying optimal conditions on the process increases ammonia production potential from 1890 to 2179 mol s−1.